Drug Possession: Can You Be Charged With Felony Posession if You Had Nothing on You

My question involves criminal law for the state of: Arizona

My husband was arrested yesterday in Arizona. He was driving back home to Texas after spending a week working and interviewing for another job out of state. Some guy he knows from back home happened to be taking a trip out to California supposedly to "visit his daughter" and was leaving and driving back to Texas around the same time as my husband was leaving. My husband called me on the way home and said they were going to meet up in Flagstaff, Arizona, a half way point, and grab some food together and split the cost of a hotel and catch up. As far as I'm aware, my husband had no knowledge that this guy actually had a bunch of marijuanna in his car. I'm not sure if the guy told my husband when they met up that night or not, but my husband left early yesterday morning to get back home to Texas by last night. He called me after he left the hotel to let me know he was on his way, and he didn't say much about his friend, but it didn't sound like they were traveling "together" it sounded like they had left about 30 or more minutes apart from each other?

My husband called me from an Arizona jail yesterday afternoon and said that his friend had been pulled over and arrested for having "a BUNCH of marijuanna in his car." And the police had pulled over my husband apparently because he had a Texas plate also and then they discovered that they had called each other several times (to arrange meeting each other) and had stayed at the same hotel the night before last. So they thought my husband had drugs on him as well. But he didn't. My husband has been a goody goody for over 20 years! He does have a history from when he was about 18, but he has completely cleaned up and not messed around at all! But because of his history, they are giving him a hard time.

I called the jail this morning and they told me he had been charged with a FELONY posession of drugs, and also felony of drug paraphenelia? Can they do that? and is posession of paraphenelia even a felony? I honestly don't think he had anything on him! He told me we had nothing to worry about, and I thought he would be out by now after it all got cleared up, but now he has FELONY charges?!?!? He said they didn't impound the car or anything, and that it could be picked up? If they had found drugs in his car, wouldn't they keep the car?

I know nothing about how this stuff works, and I don't even know what the difference is between felony and misdermeanor or if there's any other level, but I know that when the lady told me "felony" she made it sound like it was a bad thing?